Feasibility Of Lasik Surgery Using Ray Tracing Technology In The Clinic

Ray tracing is a novel refractive treatment that differs from standard laser-assisted in situ keratomileusis (LASIK) by determining individualized ablation profiles based on measurements of each unique patient’s optical elements. This study aimed to determine the feasibility and challenges of incorporating this technology into clinical practice.

Sydney, Australia

A retrospective non-randomised chart review of consecutive patients at a single centre in Sydney Australia from February 2022. Overall, 400 patients (800 eyes) were recruited, and inclusion criteria included myopic adults aged 18 years or older who underwent bilateral laser surgery using ray tracing technology with nil co- existing ocular conditions or previous ocular surgery. A minimal pupil size of 5mm is necessary to achieve a sufficient optical zone. Patients with smaller pupils were placed in a dark room underwent cycloplegic refraction if needed. Feasibility parameters included number of scans and time taken per eye, rates of screening failure and operator utility.

The average number of scans per eye when initially incorporated into clinical practice in Feb 2022 was 7.0 compared to 4.2 in Dec. The average screening time without cycloplegia was 5.1 and 2.4 mins (p<0.05) respectively in Feb and Dec. In 7.6% of cases where pupils were <5mm, cycloplegic refraction was performed, taking 63.3 and 55.2 mins respectively in Feb and Dec. In 3 cases both measures failed to achieve a pupil size >5mm and standard LASIK was performed instead. Operator usability was rated ‘easy/feasible to obtain’ in 89.9% of cases.

Ray tracing laser surgery can be feasibly incorporated into routine clinic practice with a low screening failure rate. Device familiarity increases speed and efficacy. Users should be aware of the increased burden to clinic flow posed for cases necessitating cycloplegic refraction and consider accommodating measures.